Other than the hints she has left on national television, it is still unclear what, exactly, led to Ms. Newman’s abrupt departure after a nearly yearlong tenure punctuated by conflicts with other White House aides, a lavish wedding at Trump International Hotel in Washington and a public meltdown at a conference for black journalists. Whatever the catalyst, her departure was handled by Mr. Kelly; the White House counsel, Donald F. McGahn II; and Joseph Hagin, a deputy chief of staff.

On Facebook, Armstrong Williams, a conservative media personality and a friend of Ms. Newman’s, noted that her departure had closely followed the loss by Mr. Trump’s preferred candidate in the Alabama Senate race, “Funny how her story is knocking Roy Moore off front pages.” On Friday, Ms. Newman declined to comment.

Ms. Newman’s time came to an end in the Situation Room during a meeting with Mr. Kelly. It is an unusual place to hold a discussion about employment, but one where the backdrop is both intimidating and quiet, perhaps to calm an exchange that had the potential to spiral out of control.